An impossible and insane thought ???

[Pennypacker]

Sinclairuser, perhaps I should have stated I was strictly talking in a metal detector context, and even there some digital accessories or peripherals would be and are useful.

mcgov51, I am not "poo pooing" your ideas, simply giving you some ideas and perhaps some inspirational context into the whole digital vs analog thing. Don't get so hung up on it.

I'm still waiting for you to conceptualize your "digital" filters. I hear ones made out of Willow or Hazel wood work the best.

[Carl-NC]

I will disagree twice here...

Analog has taken metal detectors about as far as it can. The future is digital. I can do brick-wall filtering and other magic tricks in digital that just cannot be done in analog no matter how many opamps I throw at it. ADCs already exceed the resolution that I can reasonably use. Everything else... ground tracking, VDI, tones, disc... is so much easier and more accurate in digital-land.

"It's not how much you know . . . It's how much you care that matters ?"

No, it's really how much you know. People who care deeply, but don't know how to solve the problems, aren't the people who are going to solve the problems.

- Carl

[mcgov51]

Carl you have appreciation for the potential of digital . . . good. What I like is that it lends itself to precise manipulation (recording, filtering without any degradation).
Also, in this case is . . . if you care enough . . . and know it will work . . . but don't have all of the knowledge necessary to make it work . . . you will seek out the collaboration of the right people who know how to make it work. There's no shame in that . . .

Pennypacker - Willow and Hazel wood are poo poo terms and condesending. Let the experts talk. You need to take your agenda elsewhere . . . Carl ???

[Overtheedge]

Well I gotta throw in my unqualified opinion.
Yes digital can do marvelous signal processing, however it is dependent upon firmware, software and still subject to analog conversion at least twice. The return signal detected is analog. The processed signal is converted back to analog for the user.

But, digital is cut and dried. You either save data or discard it in processing. No fine signal nuances available for personal, that is the stuff between your ears, processing. For many, if not most, the complexity is NOT an issue. For hardware hackers it is. It is mighty hard to hack software with hardware.

That being said, we are moving into a digital world because of price points. Digital design is cheaper all around. Analogue designs are on their way out just as thru-hole PCBs are. I used to buy #59 resharps for drilling my own PCBs. I haven't seen many available the last few years. Old RF geeks like me are dying off, perhaps good riddance too.

So that being said, show us your designs mcgov51 and I'll show you mine. Be forewarned, I'm an analogue guy with a specific purpose for my MD needs.
-----------------
It is ALWAYS what you know. Where folks get in trouble, and I'm real good at this, is not knowing what I think I know. I don't mind being wrong so much, it is staying wrong that irritates me. So I buy books and study. I ask questions and sometimes stick my posterior out to get bit. It is all part of the learning process.

The opinions and ideas of 10,000 people is absolutely worthless if they don't know anything about the subject.

Having been an e-tech, I can assure you that engineers design some serious whiz-bangs. Then they turn them over to e-techs to get them working. Unfortunately my programming days went out with Turbo-Basic. I must be a genuine anachronism.
eric

[Pennypacker]

Filtering, VDI, tones etc are all digital peripherals, which I did say was useful. The electronics are just a digital interface to an analog device.

At it's core a MD is an analog device, the primary purpose of the electronics is to excite a coil, which does what it pleases, in an analog fashion.

The coil is the metal detector. Targets do not resonate digitally either. Radio waves are analog entities.

The next significant advancement will be on this analog, physical front, this will trickle down to better information for the digital bells and whistles to use.

Think inside the box.

[Davor]

Software defined radios are a reality, and so are digitally defined metal detectors. Some processing is easier in digital world, but the foundations are exactly the same for both analogue and digital.

As a hobbyist with no aspirations for secrecy in designs, and general liking for analogue, I tend to prefer solutions that co-operate with one's cognitive apparatus, rather than pointless bells and whistles. To me a good detector is the one you understand from the moment of first switch-on, that provides a direct indication of the physical phenomena being detected. Are there many such detectors out there? Surprisingly not, and especially not among the digital crop.

The most ridiculous of all are detectors that require special training to grasp their diddle-doodle. All such devices are digital. If you encounter a crowd of confounded detectorists literally beating about the bush with their digital detectors obviously having no clue - they are just having their practical lesson.

I also noticed that people regard their overpriced digital devices with pride, but also that some other people regard their analogue devices with love.

[mcgov51]

I'll be darn ! What else . . . help us out . . . I am in the box.

Do you think further digital audio progress can be made to work more effectively with the current analog, physical front . . . ?
because to me and many others it doesn't seem like the final audio product is being handled very well ? We can currently force
things to go deeper but Carl and the others are right . . . it will just make the Locomotive scream louder.

Seems like those bells and whistles were needed and were possible years ago? But that's neither here nor there.
I'm just saying . . .

I don't know what I don't know?
So if we each share what we do know or learn we will piece something interesting together.
We invite more folks with a positive attitude to participate . . . please chime in.

AGREED ?

*And Thank You Davor - I can appreciate your point of view.
2 of my 3 MD's ( the 1266X and CZ-20/21) are purely analogue as far as I know.

[Carl-NC]

McGov, I understand what you're saying, but you're a little late to the party. When you walked in the door, you suggested we should have a party, but this party's been running now for 12 years or more. Maybe we're dancing a little slower than you think we ought to, but most of us have other parties we have to attend, and some of us are just too damned old to dance any faster. But if there's one thing we have, it's a positive attitude. And fun... we have fun, too.

[Pennypacker]

mcgov51, stick with the program lets start talking filters already.

What is needed is real time discrimination of analog audio output.

Perhaps the solution is to not discriminate at all, but to add peaks in response for desired targets.

I suppose it could work similar in fashion to a RIAA filter in a record player, that is how you could augment certain bands in the conductivity range.

Audio output of existing analog MDs should also have their audio frequency response expanded.

My ideal detector would have the feel of a Dave J style of detector but with the 99 tone audio bandwidth from say an X Terra series detector. (Main difference being the audio tones are not fixed synthesized tones like they are in the X Terra)

What needs to be sorted out is how to zoom in and expand the audio response of something similar Dave Johnson designed detector, but with the ability to generate multiple simultaneous, real time audio responses.

I want to be able to "hear" the copper and the iron at the same time, I'll explain:
Instead of fixed toned synthesized sounds of digital interfaces, which can only jump around on, or show only one TID on complex targets (multiple targets in close proximity), my detector will play real-time multiple frequency audio tones, that when used on a complex target will basically play "chords" similar to that on a guitar or piano.

[Qiaozhi]

I want to be able to "hear" the copper and the iron at the same time, I'll explain:
Instead of fixed toned synthesized sounds of digital interfaces, which can only jump around on, or show only one TID on complex targets (multiple targets in close proximity), my detector will play real-time multiple frequency audio tones, that when used on a complex target will basically play "chords" similar to that on a guitar or piano.

It sounds like [pun intended] that you're asking for an audio VCO output that corresponds to the phase of the target.
Personally, I think the sheer amount of audio infomation would drive you mad after only a few minutes.

[Pennypacker]

Multiple VCOs that mix, it would sound alright.

[Davor]

You might wish to reconsider this notion after reading something like this:
Miller, G. A. (1956). "The magical number seven, plus or minus two: Some limits on our capacity for processing information". Psychological Review 63 (2): 81–97

Guess none of the authors of diddle-doodle machines did. Your machine is the tool, not the feature presentation, and the things in the ground are those that need to come out instead of the cacophony they produce by close proximity to such an elaborate scarecrow organ.

[Pennypacker]

Thank you that is an interesting read.

[Skippy]

I like the 'scarecrow organ' analogy. Tom Dankowski refers to excessive diddle-doodle as 'like a hillbilly jug band'. Personally, I think the opportunity to present audio information in some form of stereo could be worth doing. Something more sophisticated than Left-ear = Disc, Right-ear = All-metal, but not really exotic like binaural.

[Altra]

Personally, I think the opportunity to present audio information in some form of stereo could be worth doing. Something more sophisticated than Left-ear = Disc, Right-ear = All-metal, but not really exotic like binaural.

Jerry Tyndall, has been doing the stereo all metal/Disc since the 1980's
in his line of Nautilus metal detectors. Original new ideas in this industry are becoming harder to think up.


http://www.nautilusmetaldetectors.co...tnautilus.html